Padlock-receiving locking attachment for pivotable operating handles of electrical control devices



- Oct. 26, 1965 J. A. THARP ETAL PADLOCK- EIVING LOG G ATTACHMENT FOR BLE OF PIV OPERAT DLES HAN ELECTRICAL CONTROL DEVICES Filed 0 United States Patent Oflice 3,214,534 Patented Get. 26, 1965 3,214,530 PADLOCK-RECEIVING LOCKING ATTACHMENT FOR PIVOTABLE OPERATING HANDLES OF ELECTRICAL CONTRGL DEVICES James A. Tharp and Thomas N. Batt, Cedar Rapids, Iowa, assignors to Square D Company, Park Ridge, Ill., a corporation of Michigan Filed Oct. 19, 1962, Ser. No. 231,762 4 Claims. (Cl. 200-42) This invention relates generally to means for locking operating handles of electrical devices such as switches and circuit breakers, and more particularly to a device which is readily attachable to the operating handle of a molded case circuit breaker exteriorly of the case thereof and which is adapted to receive a padlock for securing the device to the operating handle and thus locking the handle selectively in on or 011 positions.

An object of the invention is to provide an improved handle locking device for operating handles of electrical switches and circuit breakers.

Another object is to provide a handle locking device which is economical to manufacture and is readily attachable to the operating handle of a circuit breaker or switch without alteration of the handle, the device being intended for use in conjunction with a padlock.

Other objects and advantages will become apparent from the following specification wherein reference is made to the accompanying drawings, in which:

FIGURE 1 is a perspective view of a molded case circuit breaker having a handle locking device constructed in accordance with the invention secured to the operating handle thereof and a padlock secured to the locking device;

FIGURE 2 is an exploded perspective view of the embodiment of the invention shown in FIGURE 1;

FIGURE 3 is an enlarged sectional view taken substantially along the line 3-3 of FIGURE 1, but showing one of the side frame members pivoted upwardly for installation of the central plate member on the handle of the circuit breaker;

FIGURE 4 is a sectional view taken substantially along the line 44 of FIGURE 5 and illustrates a preferred embodiment of the invention;

FIGURE 5 is a sectional view taken substantially along the line 5-5 of FIGURE 4;

FIGURE 6 is an exploded perspective view of the embodiment of FIGURES 4 and 5; and

FIGURE 7 is a sectional view similar to FIGURE 5 but showing the parts of the locking device in their relative positions for installation on the operating handle.

' In the embodiment of the invention shown in FIG- URES 1-3, -a three piece handle locking device 10 includes an elongated flat plate member or handle restraining plate 11 and a pair of identically formed frame members or locking members 12. The restraining plate 11 is generally rectangular with rounded opposite end portions 13 and 14 and is provided intermediately of its ends with contoured recess 15 enlarge-d at its inner end and adapted to transversely receive a correspondingly shaped enlarged outer end portion of a pivotally mounted operating handle 16 of a circuit breaker or switch 18.

Each locking member 12 is generally U-shaped, but the free end portions 20 and 21 of the respective legs of the U are outwardly bent so as to extend substantially parallel to the bight portion 22 of the U. The end portions 20 and 21 are rounded to correspond respectively with the end portions 13 and 14 of the restraining plate 11. The locking members 12 are symmetrically disposed on opposite sides of the restraining plate 11 with the end portions 20 in engagement with opposite sides of the end portion 13. Each end portion 20 is provided with a hole 24 and the end portion 13 is provided with a corresponding hole 17 for the reception of a rivet 26 which holds the locking members 12 and restraining plate 11 in assembled relationship while allowing them to pivot thereon with respect to each other.

Each end portion 21 is provided with a hole 28 and the end portion 14 is provided with a corresponding hole 19 for the reception of the shackle 29 of a padlock 30. To attach the locking device 10 to the handle 16, the locking members 12 are pivoted out of alignment with the restraining plate 11 as shown in FIGURE 3 and the handle 16 is inserted transversely in the recess 15. The locking members 12 are then pivoted back into alignment with the restraining plate 11 to align the holes 28 with the hole 19 and the padlock shackle 29 is inserted through these holes as shown in FIGURE 1 to retain the locking members 12 and the restraining plate 11 in alignment and thus secure the locking device to the handle. The locking device 10 cannot then be removed from the handle 16 because the shackle 29 prevents the locking members 12 from being pivoted out of alignment with the retaining plate 11 to allow the handle 16 to be transversely removed from the recess 15, and the enlarged outer end portion of the handle 16 in conjunction with the corresponding shape of the recess 15 prevents removal of the restraining plate 11 axially of the handle 16. When the locking device is thus secured on the handle 16 in one of the on and 0d positions of the handle, the handle cannot be pivoted to the other of its on and off positions because of interference between the bight portions 22 of the locking members 12 and the casing of the circuit breaker 18.

In the embodiment of the invention shown in FIG- URES 47, a two-piece handle locking device 40 includes a generally flat elongated plate member or handle restraining plate 41 and a generally U-shaped frame member or locking bracket 42. The restraining plate 41 is generally rectangular but is provided at one end with a longitudinally extending tongue portion 44 having a pair of oppositely disposed rectangular notches 46 adjacent an extreme outer end portion 47 of the tongue portion. At its other end, the restraining plate 41 is provided with a hole 48, and the leg portions of the U- shaped locking bracket 42 are provided adjacent their free ends respectively with a pair of corresponding holes '49, the holes 48 and 49, when aligned, being adapted to receive a shackle of a padlock. Between the hole 48 and the tongue portion 44 the restraining plate 41 is provided with a contoured recess 50 similar to the recess 15 of the restraining plate 11 and enlarged at its inner end for transversely receiving a correspondingly shaped outer end portion of an operating handle such as the handle 16. The bight portion 52 of the locking bracket 42 is provided with a generally rectangular slot 53 adapted to receive the tongue portion 44 of the restraining plate 41.

In assembling the restraining plate and locking bracket, the tongue portion 44 is inserted through the slot 53 and the outer end portion 47 is twisted substantially through ninety degrees with respect to the remainder of the tongue portion, as shown .in FIGURES 4, 5, and 7, the actual twisting of the material taking place in a weakened portion 54 of the tongue portion between the notches 46. The slot 53 is of a width which provides only a small amount of clearance for the tongue portion 44, so that when the portion 54 is twisted, it is widened out in the direction of the width of the slot 53 to an extent that its overall width is greater than the width of the slot. The twisted portion 54 thus retains the restraining plate 41 in assembled relationship with the locking bracket 42, though the tongue portion 44 may be moved reciprocally in hte slot 53 between the twisted portion 54 and the inner end of the tongue portion 44 adjacent the main portion of the restraining plate 41. If the slot 53 were made slightly wider than the twisted portion 54, or in case of wear of the twisted portion 54, the outer end portion 47 would retain the restraining plate 41 and locking bracket 42 in assembled relationship. The height of the slot 53 is greater than the height of the tongue portion 44 to provide a substantial amount of clearance and enable the restraining plate 41 to be pivoted with respeet to the locking bracket 42 to position the contoured recess 50 out of alignment with the leg portions of the locking bracket 42, as shown in FIGURE 7. The recess 50 can then transversely receive the handle 16, after which the locking bracket 42 may be pivoted back into alignment with the restraining plate 41 and into engagement with the casing 18, the holes 48 and 49 aligned, and a shackle of a padlock inserted therein to lock the locking device 40 on the handle 16 and lock the handle 16 in position.

Various modifications may be made in the structures disclosed without departing from the spirit and scope of the invention.

We claim:

1. A locking device for a rigid operating handle protruding outwardly of a casing of an electrical device, the handle being pivotable about an axis disposed inwardly of an outer surface of the casing and having a relatively narrow intermediate portion and an enlarged outer end portion in planes perpendicular to its pivotal axis, said locking device being mountable on said handle entirely outside said casing and comprising an elongated, edgewise rigid, fiat plate member mountable on said handle, a frame encompassing the protruding portion of said handle when said locking device is mounted on said handle, said frame bearing against said outer surface of said casing when said locking device is mounted on said handle and an attempt is made to operate said handle, said frame including a pair of spaced, parallel, fiat portions extending perpendicularly to said pivotal axis of said handle in closely spaced relationship respectively to opposite side surfaces of said handle when said locking device is mounted on said handle, said plate member being pivotally mounted adjacent one end on said frame intermediately and adjacent one end thereof, said plate member and frame being adapted to receive a shackle of a padlock adjacent the other ends thereof, the total clearance between said spaced flat portions of said frame and said handle being less than the distance between said plate member and one of said spaced flat portions of said frame, and means preventing removal of said plate member from said handle in a direction perpendicular to said pivotal axis of said handle and accommodating removal of said plate member from said handle solely in a direction parallel to said pivotal axis of said handle when said plate member is mounted on said handle, said means comprising a contoured recess in an edge portion of said plate member between the ends thereof, said contoured recess having an enlarged inner end portion wider than said enlarged outer end portion of said handle and having a relatively narrow outer end portion wider than said relatively narrow intermediate portion of said handle but narrower than said enlarged outer end portion of said handle, the rigidity of said handle and the edgeWise rigidity of said plate member preventing said enlarged outer end portion of said handle from passing through said relatively narrow outer end portion of said contoured recess when an attempt is made to remove said plate member from said handle in a direction parallel to said plate member and perpendicular to said pivotal axis of said handle.

2. A locking device for a rigid operating handle protruding outwardly of a casing of an electrical device, the handle being pivotable about an axis disposed inwardly of an outer surface of the casing and having a relatively narrow intermediate portion and an enlarged outer end portion in planes perpendicular to its pivotal axis, said locking device being mountable on said handle entirely outside said casing and comprising a generally U-shaped frame straddling the protruding portion of said handle when said locking device is mounted on said handle, said frame bearing against said outer surface of said casing when said locking device is mounted on said handle and an attempt is made to operate said handle, said frame including a bight portion having a pair of spaced, parallel, flat leg portions extending therefrom perpendicular to said pivotal axis of said handle in closely spaced relationship respectively to opposite side surfaces of said handle when closely spaced relationship respectively to opposite side surfaces of said handle when said locking device is mounted on said handle, an elongated, edgewise rigid, flat plate member said bight portion having a slot therethrough and said plate member having a tongue portion extending longitudinally from one end thereof through said slot, said tongue portion being deformed adjacent its outer end to retain said plate member in assembled relationship with said frame while accommodating relative pivotal movement therebetween, said leg portions having holes extending respectively therethrough adjacent their free ends, said plate member having a hole extending therethrough adjacent the other end thereof, said holes in said leg portions and plate member being adapted to receive a shackle of a padlock to lock the locking device on said handle and lock said handle in position, the total clearance between said leg portions of said frame and said pivotable operating handle being less than the distance between said plate member and one of said leg portions of said frame, and means preventing removal of said plate member from said handle in a direction perpendicular to said pivotal axis of said handle and accommodating removal of said plate member from said handle solely in a direction parallel to said pivotal axis of said handle when said plate member is mounted on said handle, said means comprising a contoured recess in an edge portion of said plate member between the ends thereof, said contoured recess having an enlarged inner end portion wider than said enlarged outer end portion of said handle and having a relatively narrow outer end portion wider than said relatively narrow intermediate portion of said handle but narrower than said enlarged outer end portion of said handle, the rigidity of said handle and the edgewise rigidity of said plate member preventing said enlarged outer end portion of said handle from passing through said relatively narrow outer end portion of said contoured recess when an attempt is made to re move said plate member from said handle in a direction parallel to said plate member and perpendicular to said pivotal axis of said handle.

3. A locking device for a rigid operating handle protruding outwardly of a casing of an electrical device, the handle being pivotable about an axis disposed inwardly of an outer surface of the casing and having a relatively narrow intermediate portion and an enlarged outer end portion in planes perpendicular to its pivotal axis, said locking device being mountable on said handle entirely outside said casing and comprising a generally U-shaped frame bearing against said outer surface of said casing when said locking device is mounted on said handle and an attempt is made to operate said handle, said frame having a bight portion and a pair of spaced, parallel, flat leg portions extending from said bight portion and straddling the protruding portion of said handle when said locking device is mounted on said handle, said leg portions extending perpendicularly to said pivotal axis of said handle in closely spaced relationship respectively to opposite side surfaces of said handle when said locking device is mounted on said handle, an elongated, edgewise rigid, flat plate member said bight portion having a slot therethrough and said plate member having a tongue portion extending longitudinally from one end thereof through said slot, said tongue portion being deformed adjacent its outer end to retain said plate member in assembled relationship with said frame while accommodating relative pivotal movement therebetween, said leg portions having holes extending respectively therethrough adjacent their free ends, said plate member having a hole extending therethrough adjacent the other end thereof, said holes in said leg portions and plate member being adapted to receive a shackle of a padlock to lock the locking device on said handle and lock said handle in position, the total clearance between said leg portions of said frame and said pivotable operating handle being less than the distance between said plate member and one of said leg portions of said frame, and means preventing removal of said plate member from said handle in a direction perpendicular to said pivotal axis of said handle and accommodating removal of said .plate member from said handle solely in a direction parallel to said pivotal axis of said handle when said plate member is mounted on said handle, said means comprising a contoured recess in an edge portion of said plate member between the ends thereof, said contoured recess having an enlarged inner end portion wider than said enlarged outer end portion of said handle and having a relatively narrow outer end portion wider than said relatively narrow intermediate portion of said handle but narrower than said enlarged outer end portion of said handle, the rigidity of said handle and the edgewise rigidity of said plate member preventing said enlarged outer end portion of said handle from passing through said relatively narrow outer end portion of said contoured recess when an attempt is made to remove said plate member from said handle in a direction parallel to said plate member and perpendicular to said pivotal axis of said handle.

4. A locking device for a rigid operating handle protruding outwardly of a casing of an electrical device, the handle being pivotable about an axis disposed inwardly of an outer surface of the casing and having a relatively narrow intermediate portion and an enlarged outer end portion in planes perpendicular to its pivotal axis, said locking device being mountable on said handle entirely outside said casing and comprising an elongated, edgewise rigid, flat plate member mountable on said handle, a pair of generally U-shaped frame members each having a bight portion and a pair of legs extending from said bight portion, the free end portions of said legs being outwardly bent to extend substantially parallel to their respective bight portions, said frame members being symmetrically disposed on opposite sides of said plate member and substantially surrounding the protruding portion of said handle when said locking device is mounted on said handle, said bight portions of said frame members bearing against said outer surface of said casing when said locking device is mounted on said handle and an attempt is made to operate said handle, one outwardly bent free end portion of each of said frame members and one end portion of said plate member being pivotally connected the other outwardly bent free end portion of each of said frame members and the other end portion of said plate member being adapted to receive a shackle of a padlock to lock the locking device on said handle and lock said handle in position, said bight portions of said frame members extending perpendicular to said pivotal axis in closely spaced relationship respectively to opposite side surfaces of said handle when said locking device is mounted on said handle, the total clearance between said bight portions and said handle being less than the distance between one of said bight portions and said plate member, and means preventing removal of said plate member from said handle in a direction perpendicular to said pivotal axis of said handle and accommodating removal of said plate member from said handle solely in a direction parallel to said pivotal axis of said handle when said plate member is mounted on said handle, said means comprising a contoured recess in an edge portion of said plate member between the ends thereof, said contoured recess having an enlarged inner end portion wider than said enlarged outer end portion of said handle and having a relatively narrow outer end portion wider than said relatively narrow intermediate portion of said handle but narrower than said enlarged outer end portion of said handle, the rigidity of said handle and the edgewise rigidity of said plate member preventing said enlarged outer end portion of said handle from passing through said relatively narrow outer end portion of said contoured recess when an attempt is made to remove said plate member from said handle in a direction parallel to said plate member and perpendicular to said pivotal axis of said handle.

References Cited by the Examiner UNITED STATES PATENTS 2,192,060 2/40 Wise. 2,813,938 11/57 Speizman ZOO-42 BERNARD A. GILHEANY, Primary Examiner.

ROBERT K. SCHAEFER, Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,214,530 October 26, 1965 James A. Tharp et a1.

It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 4, line 14, beginning with "when closely spaced", strike out all to and including "being adapted to", in line 27, same column 4, and insert instead when said operating device is mounted on said handle, an elongated, edgewise rigid, flat plate member mountable on said handle, said plate member having one end portion pivotally mounted on the bight portion of said generally U-shaped frame, the free end portions of the leg portions of said generally U-shaped frame and the other end portion of said plate member being adapted to Signed and sealed this l4th day of June 1966.

(SEAL) Attest:

ERNEST W. SWIDER EDWARD J. BRENNER \ttesting Officer Commissioner of Patents 

1. A LOCKING DEVICE FOR A RIGID OPERATING HANDLE PROTRUDING OUTWARDLY OF A CASING OF AN ELECTRICAL DEVICE, THE HANDLE BEING PIVOTABLE ABOUT AN AXIS DISPOSED INWARDLY OF AN OUTER SURFACE OF THE CASING AND HAVING A RELATIVELY NARROW INTERMEDIATE PORTION AND AN ENLARGED OUTER END PORTION IN PLANES PERPENDICULAR TO ITS PIVOTAL AXIS SAID LOCKING DEVICE BEING MOUNTABLE ON SAID HANDLE ENTIRELY OUTSIDE SAID CASING AND COMPRISING AN ELONGATED, EDGEWISE RIGID, FLAT PLATE MEMBER MOUNTABLE ON SAID HANDLE, A FRAME ENCOMPASSING THE PROTRUDING PORTION OF SAID HANDLE WHEN SAID LOCKING DEVICE IS MOUNTED ON SAID HANDLE, SAID FRAME BEARING AGAINST SAID OUTER SURFACE OF SAID EASING WHEN SAID LOCKING DEVICE IS MOUNTED ON SAID HANDLE AND AN ATTEMPT IS MADE TO OPERATE SAID HANDLE, SAID FRAME INCLUDING A PAIR OF SAPCED, PARALLEL, FLAT PORTIONS EXTENDING PERPENDICULARLY TO SAID PIVOTAL AXIS OF SAID HANDLE IS CLOSELY SPACED RELATIONSHIP RESPECTIVELY TO OPPOSITE SIDE SURFACES OF SAID HANDLE WHEN SAID LOCKING DEVICE IS MOUNTED ON SAID HANDLE, SAID PLATE MEMBER BEING PIVOTALLY MOUNTED ADJACENT ONE END ON SAID FRAME INTERMEDIATELY AND ADJACENT ONE END THEREOF, SAID PLATE MEMBER AND FRAME BEING ADAPTED TO RECEIVE A SHACKLE OF A PADLOCK ADJACENT THE OTHER ENDS THEROEF, THE TOTAL CLEARANCE BETWEEN SAID SPACED FLAT PORTIONS OF SAID FRAME AND SAID HANDLE BEING LESS THAN THE DISTANCE BETWEEN SAID PLATE MEMBER AND ONE OF SAID SPACED FALT PORTIONS OF SAID FRAME, AND MEANS PREVENTING REMOVAL OF SAID PLATE MEMBER FROM SAID HANDLE IN A DIRECTION PERPENDICULAR TO SAID PIVOTAL AXIS OF SAID HANDLE AND ACCOMMODATING REMOVAL OF SAID PLATE MEMBER FROM SAID HANDLE SOLELY IN A DIRECTION PARALLEL TO SAID PIVOTAL AXIS OF SAID HANDLE WHEN SAID PLATE MEMBER IS MOUNTED ON SAID HANDLE, SAID MEANS COMPRISING A CONTOURED RECESS IN AN EDGE PORTION OF SAID PLATE MEMBER BETWEEN THE ENDS THEREOF, SAID CONTOURED RECESS HAVING AN ENLARGED INNER END PORTION WIDER THAN SAID ELNARGED OUTER END PORTION OF SAID HANDLE AND HAVING A RELATIVELY NARROW OUTER END PORTION WIDER THAN SAID RELATIVELY NARROW INTERMEDIATE PORTION OF SAID HANDLE BUT NARROWER THAN SAID ENLARGED OUTER END PORTION OF SAID HANDLE, THE RIGIDITY OF SAID HANDLE AND THE EDGEWISE RIGIDITY OF SAID PLATE MEMBER PREVENTING SAID ENLARGED OUTER END PORTION OF SAID HANDLE FROM PASSING THROUGH SAID RELATIVELY NARROW OUTER END PORTION OF SAID CONTOURED RECESS WHEN AN ATTEMPT IS MADE TO REMOVE SAID PLATE MEMBER FROM SAID HANDLE IN A DIRECTION PARALLEL TO SAID PLATE MEMBER AND PERPENDICULAR TO SAID PIVOTAL AXIS OF SAID HANDLE. 